Delayed Auditory Feedback

Delayed Auditory Feedback (DAF) is a device that enables a user of the device to speak into a microphone and then hear his or her voice in headphones a fraction of a second later. Some DAF devices are hardware; DAF computer software is also available.

Delayed auditory feedback has been used with a directional microphone and speaker to create a device[3] intended to silence an individual speaker using the mental stress induced in people unused to the effect.[4]

There are now also different mobile apps available that use DAF in phone calls.[5]